Diffusion in the matrix of granitic rock: field test in the Stripa Mine

Keyword(s):  
1981 ◽  
Vol 11 ◽  
Author(s):  
Lars Birgersson ◽  
Ivars Neretnieks

A migration experiment with the objective to investigate the existence of a connected pore system in undisturbed rock has been performed in the Stripa mine at the 360 m-level.


1990 ◽  
Vol 26 (11) ◽  
pp. 2833-2842 ◽  
Author(s):  
Lars Birgersson ◽  
Ivars Neretnieks
Keyword(s):  

1987 ◽  
Vol 112 ◽  
Author(s):  
Lars Birgersson ◽  
Ivars Neretnieks

AbstractThree similar migration experiments in the matrix of granitic rock are presented. The experiments have been carried out in “undisturbed” rock, that is rock under its natural stress environment. Since the experiments were performed at the 360 m level (in the Stripa Mine), the rock was subjected to nearly the same conditions as the rock surrounding a nuclear waste repository as proposed in the Swedish concept (SKB).A mixture of three non-sorbing (conservative) tracers, Uranine, Cr-EDTA and I−, were injected into the granitic rock matrix for time periods of months up to years. The subsequent overcorings of the injection holes showed that the tracers had in some cases migrated at least ≈ 400 mm (measuring limit) into the rock matrix for the experiment with the longest injection time. It could also be seen that there were large differences in migration distance into the rock matrix for samples taken fairly close to each other. One example where the tracers have diffused through fissure coating (filling) material located in “undisturbed” rock is also presented.The results from all three experiments show that all three tracers have migrated through the disturbed zone close to the injection hole, through the fissure coating material and a distance into the “undisturbed” rock matrix.These results therefore indicate that dissolved compounds may migrate into the rock matrix. This migration into the rock matrix will increase the area available for sorption of radionuclides significantly and may therefore increase the migration times for radionuclides by order(s) of magnitude.Diffusivities and hydraulic conductivities obtained in this in-situ experiment compare well with those obtained in laboratory experiments.


2011 ◽  
Vol 337 ◽  
pp. 106-111
Author(s):  
Ye Han ◽  
Zhen Duo Cui ◽  
Zhao Zeng Liu ◽  
Zhao Long Chen ◽  
Lin Ba ◽  
...  

Inhibitors are frequently used for controlling sulfur corrosion in oil and gas production due to its low cost, easy operation and significant effects. In this study, a corrosion inhibitor TD-02 was prepared, and the properties of TD-02 were investigated by weight loss, SEM and electrochemistry measurements in saturated hydrogen sulfide solution. The results show that significant inhibition effect was achieved by adding TD-02 as inhibitor. A protective film is formed by adsorption of inhibitor molecules on the matrix and inhibition achieved by geometry covering. The field test results indicated that the wear of the compressor shaft was significantly inhibited, which achieves the desired results.


1987 ◽  
Vol 112 ◽  
Author(s):  
Luis Moreno ◽  
Ivars Neretnieks

SummaryRadionuclide transport through fractured media is usually calculated assuming that water flows in most of the fractures. Several observations in the field and the laboratory show that flow is very unevenly distributed in fractured crystalline rock. These observations indicate that most of the water flow takes place in a limited number of channels. The channels are seldom wider than a few meters and are often much narrower. This means that the surface of the fracture in contact with the flowing water (wetted surface) is less than one might expect.This low value of the wet surface of the fracture may considerably influence the transport of radionuclides through fractured media. If the channels do not intersect over a certain distance, then the channels may be modelled as a bundle of independent channels. Channels with a large flow and small sorption surface will carry the tracer rapidly and in large amounts.Calculations are performed for cases where channeling is assumed to take place. The most important entities to assess are the water flow distribution in the different channels, the wetted surface of the channels, the diffusivity into the rock matrix, and the sorption coefficient in the matrix. Experimental data for the water flow distribution are used and the transport of nuclides is calculated for the different channels. From these values the concentration of the effluent is determined. The results show that the retardation for the nonsorbing nuclides is negligible. Retardation is only important for the nuclides which are strongly sorbed on the granitic rock. Calculations are also done assuming other channel frequencies and other overall water flowrates.


1983 ◽  
Vol 26 ◽  
Author(s):  
Lars Birgersson ◽  
Ivars Neretnieks

ABSTRACTA migration experiment in the rock matrix is presented. The experiment has been carried out in “undisturbed” rock, that is in rock under its natural stress environment. Since the experiment was performed at the 360 m-level (in the Stripa mine), the rock was subject to nearly the same conditions as the rock surrounding a nuclear waste repository as proposed in the Swedish concept (KBS).The results show that all three tracers (Cr-EDTA, Uranine and 1-) have passed the zone disturbed by the presence of the injection hole and migrated some distance into “undisturbed” rock.These results indicate the existence of a connected micro fissure system in undisturbed rock, in which tracers (and therefore radionuclides) can migrate. Diffusivities obtained in this experiment are comparable to those obtained in laboratory experiments.


Author(s):  
Odell T. Minick ◽  
Hidejiro Yokoo

Mitochondrial alterations were studied in 25 liver biopsies from patients with alcoholic liver disease. Of special interest were the morphologic resemblance of certain fine structural variations in mitochondria and crystalloid inclusions. Four types of alterations within mitochondria were found that seemed to relate to cytoplasmic crystalloids.Type 1 alteration consisted of localized groups of cristae, usually oriented in the long direction of the organelle (Fig. 1A). In this plane they appeared serrated at the periphery with blind endings in the matrix. Other sections revealed a system of equally-spaced diagonal lines lengthwise in the mitochondrion with cristae protruding from both ends (Fig. 1B). Profiles of this inclusion were not unlike tangential cuts of a crystalloid structure frequently seen in enlarged mitochondria described below.


Author(s):  
R. A. Ricks ◽  
Angus J. Porter

During a recent investigation concerning the growth of γ' precipitates in nickel-base superalloys it was observed that the sign of the lattice mismatch between the coherent particles and the matrix (γ) was important in determining the ease with which matrix dislocations could be incorporated into the interface to relieve coherency strains. Thus alloys with a negative misfit (ie. the γ' lattice parameter was smaller than the matrix) could lose coherency easily and γ/γ' interfaces would exhibit regularly spaced networks of dislocations, as shown in figure 1 for the case of Nimonic 115 (misfit = -0.15%). In contrast, γ' particles in alloys with a positive misfit could grow to a large size and not show any such dislocation arrangements in the interface, thus indicating that coherency had not been lost. Figure 2 depicts a large γ' precipitate in Nimonic 80A (misfit = +0.32%) showing few interfacial dislocations.


Author(s):  
S. Mahajan ◽  
M. R. Pinnel ◽  
J. E. Bennett

The microstructural changes in an Fe-Co-V alloy (composition by wt.%: 2.97 V, 48.70 Co, 47.34 Fe and balance impurities, such as C, P and Ni) resulting from different heat treatments have been evaluated by optical metallography and transmission electron microscopy. Results indicate that, on air cooling or quenching into iced-brine from the high temperature single phase ϒ (fcc) field, vanadium can be retained in a supersaturated solid solution (α2) which has bcc structure. For the range of cooling rates employed, a portion of the material appears to undergo the γ-α2 transformation massively and the remainder martensitically. Figure 1 shows dislocation topology in a region that may have transformed martensitically. Dislocations are homogeneously distributed throughout the matrix, and there is no evidence for cell formation. The majority of the dislocations project along the projections of <111> vectors onto the (111) plane, implying that they are predominantly of screw character.


Author(s):  
E. Keyhani

The matrix of biological membranes consists of a lipid bilayer into which proteins or protein aggregates are intercalated. Freeze-fracture techni- ques permit these proteins, perhaps in association with lipids, to be visualized in the hydrophobic regions of the membrane. Thus, numerous intramembrane particles (IMP) have been found on the fracture faces of membranes from a wide variety of cells (1-3). A recognized property of IMP is their tendency to form aggregates in response to changes in experi- mental conditions (4,5), perhaps as a result of translational diffusion through the viscous plane of the membrane. The purpose of this communica- tion is to describe the distribution and size of IMP in the plasma membrane of yeast (Candida utilis).Yeast cells (ATCC 8205) were grown in synthetic medium (6), and then harvested after 16 hours of culture, and washed twice in distilled water. Cell pellets were suspended in growth medium supplemented with 30% glycerol and incubated for 30 minutes at 0°C, centrifuged, and prepared for freeze-fracture, as described earlier (2,3).


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